Mathematics fun

[Krys TOFF]

Following the mathematics discuss on "sports and freetime" topic, let's have some mathematics fun here.


Game 1 :
Take somebody's age (in years, between 1 and 99) => number A
Calculate A*10 => B
Choose a number between 1 and 9 => C
Calculate C*9 => D
Calculate B-D=>E
Tell me your number E, and I'll tell you the age you thought about.


Game 2 :
Take a birth date in full format ddmmyyyy (d=day, m=month and y=year) => A
Reverse the numbers of A => B
Calculate |A-B|=abs(A-B) => C (this means if A-B is under 0, keep the number without the minus part : if A=5 and B=7, A-B=-2 but |A-B|=2)
This C number is composed of 8 figures maximum. Suppress one of these figures and put the remaining figures in any order to form another number.
Tell me this number, and I'll tell you the missing figure.

Example for game 2 :
A=21071970 for me because I was born 21st of July 1970
B=07917012
|A-B|=|21071970-07917012=13161258=C
C figures = 1, 3, 1, 6, 1, 2, 5 and 8.
Imagine I suppress figure 3. It remains 1 1 6 1 2 5 8. I mix it => new number is 8116215.
Tell me 8116215 and I'll tell you that you selected figure 3. I promise.


Now, I wait for your numbers for the 2 games and I'll tell you the answers. :-D

I'll tell you how I do for knowing the answer (mathematics explanation) next week. But before, play these 2 games with me. :wink:
Argammon and Renato, if you already know the way to guess the good results, don't tell it until some members have played the game before.

[CTG]

Too easy, guy. We had some same level exercises in elementary school math contest at age 10-12.  :-D

[Argammon]

Yes those are well knowns.Especially the first game.

[BonzaiJoe]

There is a very simple problem with these games, Krys .

Many people here are mathematically educated, like CTG, Argammon, Renato... And so they will easily see through the games, or have known them beforehand. They will not find fun in playing.

Others like me, are humanistically educated, and that's because we hate mathematics :-) So for us, mathematics is the opposite of fun, and we will not have fun playing :-)

So good luck finding someone to play with  :wink:

[CTG]

Many people here are mathematically educated, like CTG...

Don't hurt me! My world is chemistry, not math.  :-D

[BonzaiJoe]

Neither is Argammon's, but they are both based on mathematics. Mine is not...

[CTG]

Neither is Argammon's, but they are both based on mathematics. Mine is not...

Poor Bonzai Joe...  :-D

[Usrin]

OK, here's a number for Game 2: 8810910. I really wonder how you can guess whether the missing figure is 0 or 9.

Btw, your example wasn't correct: 21071970-07917012=13154958 (and not 13161258). :!:

[JTK]

Here's my number: 163969. Now I await your answer.  :?

[Krys TOFF]

OK, here's a number for Game 2: 8810910. I really wonder how you can guess whether the missing figure is 0 or 9.

Oh, damn ! I forgot to add one point of the rules : you can't select 0 as the suppressed number. :-D
So that's right : missing number is 9 or 0. 50% chance for me... Let's say 9. :lol:

Here's my number: 163969. Now I await your answer. :?

Missing number is 2. :wink:

[Usrin]

Oh, damn ! I forgot to add one point of the rules : you can't select 0 as the suppressed number. :-D
So that's right : missing number is 9 or 0. 50% chance for me... Let's say 9. :lol:

You bet wrong, it was 0. :-D

[Krys TOFF]

Oh, damn ! I forgot to add one point of the rules : you can't select 0 as the suppressed number. :-D
So that's right : missing number is 9 or 0. 50% chance for me... Let's say 9. :lol:

You bet wrong, it was 0. :-D

As I said, it was 50% chance. :wink: